Darkest Hour movie director Joe Wright found an interesting way to keep spirits up during the making of the award-winning Winston Churchill war biopic. Actor Samuel West uploaded a video of the moment on the British House of Commons' set when Wright encouraged 450 extras to join in a rendition of the Beatles’ “Hey Jude.” At the end of the clip, lead actor Gary Oldman appears on set and joins the fun.

“Been waiting to post this for a year,” West said via Twitter. “Joe Wright… leads 450 MPs in a warmup singing of ‘Hey Jude’ between takes. Gary Oldman as Churchill makes an entrance at the end.”

Darkest Hour, which is currently in theaters, explores Churchill’s early days as British Prime Minister during the Second World War as German leader Adolf Hitler planned to invade the island nation. Oldman won a Golden Globe for his performance and West plays Churchill’s deputy Anthony Eden, who went on to become Prime Minister in 1955.

“Hey Jude” was the longest single ever released when it arrived in 1968, and the first single launched via the Beatle’s Apple Records. It went on to spend nine weeks at the top of the U.S. charts. It was written by Paul McCartney and started out as a song intended to comfort Julian Lennon over dad John Lennon’s split with his mom Cynthia. McCartney later changed the title from “Hey Jules” when he realized the publicity wouldn’t help matters, and also because he thought it “sounded a bit better.”